제출 #1236035

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1236035		thelegendary08	Cat in a tree (BOI17_catinatree)	C++17	100 / 100	41 ms	26696 KiB

catinatree

#include<bits/stdc++.h>
#define pb push_back
#define mp make_pair
#define int long long
#define vi vector<int>
#define vvi vector<vector<int>>
#define pii pair<int, int>
#define vpii vector<pair<int, int>>
#define vc vector<char>
#define vb vector<bool>
#define mii map<int,int>
#define f0r(i,n) for(int i=0;i<n;i++)
#define FOR(i,k,n) for(int i=k;i<n;i++)
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define in(a) int a; cin>>a
#define in2(a,b) int a,b; cin>>a>>b
#define in3(a,b,c) int a,b,c; cin>>a>>b>>c
#define in4(a,b,c,d) int a,b,c,d; cin>>a>>b>>c>>d
#define vin(v,n); vi v(n); f0r(i,n){cin>>v[i];}
#define out(a) cout<<a<<'\n'
#define out2(a,b) cout<<a<<' '<<b<<'\n'
#define out3(a,b,c) cout<<a<<' '<<b<<' '<<c<<'\n'
#define out4(a,b,c,d) cout<<a<<' '<<b<<' '<<c<<' '<<d<<'\n'
#define pout(a) cout<<a.first<<' '<<a.second<<'\n'
#define vout(v) for(auto u : v){cout<<u<<' ';} cout<<'\n'
#define dout(a) cout<<a<<' '<<#a<<'\n'
#define dout2(a,b) cout<<a<<' '<<#a<<' '<<b<<' '<<#b<<'\n'
#define yn(x); if(x){cout<<"YES"<<'\n';}else{cout<<"NO"<<'\n';}
const int leg = 1e9 + 7;
const int mod = 998244353;
using namespace std;
const int mxn = 2e5 + 5;
vvi adj(mxn);
int timer = 0; int n,d;
vi sz(mxn), par(mxn), tin(mxn), dep(mxn);
pii dfs(int node, int from){
	int ret = 1; tin[node] = timer; timer++; pii ans = mp(1, 0);
	for(auto u : adj[node]){
		if(u == from)continue;
		dep[u] = dep[node] + 1;
		pii nx = dfs(u, node);
		ans.first += nx.first;
		if(nx.second + ans.second + 1 < d){
			ans = {ans.first - 1, max(nx.second + 1, ans.second)};
		}
		else{
			ans = {ans.first, min(ans.second, nx.second + 1)};
		}
	}
	return ans;
}
signed main(){
	ios::sync_with_stdio(false);
	cin.tie(NULL);
	//ifstream cin(".in");
	//ofstream cout(".out");
	cin>>n>>d;// distance must be >= d
	f0r(i,n-1){
		in(x);
		par[i+1] = x;
		adj[i+1].pb(x);
		adj[x].pb(i+1);
	}
	par[0] = -1;
	out(dfs(0, -1).first);
	/*
	vi close(n, 4e18);
	vpii w;
	f0r(i,n){
		w.pb(mp(dep[i], i));
	}
	sort(rall(w));
	*/
	
}

• Subtask 1: 11 / 11
• Subtask 2: 40 / 40
• Subtask 3: 49 / 49